Description of the Realated Art
The invention relates to a monitoring system comprising at least one camera for generating a sequence of video images of a room to be monitored, and a control circuit for setting off an alarm at a significant change of a plurality of consecutive video images.
A video-phone device, which is used for room monitoring, is known from DE-A1-38 27 928. This video-phone device is provided with a monitoring circuit which stores images supplied by a camera in the video-phone device. In a comparison circuit incorporated in the monitoring circuit, the image supplied by the camera is compared with a stored image which has been recorded a short time before and an alarm is triggered when the two images to be compared differ by a predetermined extent.
In the known video monitoring system the complete image data are processed in the monitoring circuit, so that the alarm is triggered in real time only with fast and expensive circuits.